GMTK is the Gnome Mplayer Toolkit

It includes common methods used by Gnome Mplayer and Gecko Media 
Player. The library also contains several widgets that can be used by 
other applications. Those widgets are

    gmtk_media_player - a widget that completely embeds Mplayer
    gmtk_media_tracker - a widget that manages the timeline of media
    gmtk_audio_meter - a audio visualization tool
    gmtk_output_combobox - a widget for selecting audio outputs 
                           (alsa and pulse compatible)